Transcatheter aortic valve thrombosis: incidence, clinical presentation and long-term outcomes.

Aims: To assess the incidence, management and long-term outcomes of transcatheter heart valve thrombosis (THVT).
Methods and Results: Between August 2007 and February 2016, 1396 patients were included in the Bern TAVI Registry and prospectively followed-up through echocardiographic and clinical evaluation. THVT was suspected in case of: (i) a mean transvalvular pressure gradient greater than 20 mmHg at transthoracic echocardiography, or (ii) an increase of more than 50% of the mean transvalvular pressure gradient compared with previous measurements or (iii) new symptoms or signs of heart failure with the presence of thrombus documented by transoesophageal echocardiography or multi-slice computed tomography. THVT occurred in 10 patients (0.71%) at variable time points after TAVI. Increased transvalvular pressure gradients were recorded in all patients and 7 out of 10 patients were symptomatic. Oral anticoagulant therapy (with vitamin K antagonists or non-Vitamin K antagonists) was initiated in all but two patients and resulted in normalization of transvalvular pressure gradients and amelioration of clinical status within 1 month. At long-term follow-up (between 10 and 25 months after valve thrombosis), echocardiographic findings were stable and no adverse events were reported.
Conclusion: THVT is rarely detected at routine clinical and echocardiographic evaluation after TAVI. Oral anticoagulation appears effective to normalize transvalvular gradients in the majority of cases with stable clinical and haemodynamic evolution during long-term follow-up.